Increasing diagnostic effectiveness of thyroid nodule evaluation by implementation of cell block preparation in routine US-FNA analysis

Ana Patrícia de Cristo, Heloísa Folgierini Goldstein, Carlo Sasso Faccin, Ana Luiza Maia, Marcia Silveira Graudenz
2016 Archives of Endocrinology and Metabolism  
Objective: Ultrasound-guided fine-needle aspiration (US-FNA) biopsy has proven to be an accurate and efficient tool in thyroid nodule evaluation. We evaluated whether cell block adds to the diagnostic accuracy of US-FNA. Subjects and methods: Three hundred twenty-eight consecutive patients underwent US-FNA, cytology and cell block evaluation. Six slides were prepared for each patient and stained by Papanicolaou and Giemsa techniques. The residual hemorrhagic aspirate in the syringe and needle
more » ... yringe and needle was fixed in 10% formalin and paraffin-embedded (cell block). The histological sections were examined as a complementary diagnostic tool to US-FNA. Results: The study population comprised 89% females and the mean age was 57.4 ± 13.7 years. The mean nodule size was 2.3 ± 1.2 cm. US-FNA cytological results were as follows: Bethesda I, 17.1% (n = 56); Bethesda II, 61.6% (n = 202); Bethesda III, 9.5% (n = 31); Bethesda IV, 5.8% (n = 19); Bethesda V, 2.4% (n = 8), and Bethesda VI, 3.6% (n = 12). Cell blocks were obtained in 100% of cases and were considered diagnostic in 89.6%. Combined cytological and cell block (cyto-cell block) results were as follows: unsatisfactory, 4.3% (n = 14); benign, 72.6% (n = 238); indeterminate, 11.3% (n = 37); follicular lesion, 5.8% (n = 19); suspicious for malignancy, 2.4% (n = 8), and malignant, 3.6% (n = 12). The sensitivity and specificity for cyto-cell block was 100% and 90%, respectively, and the accuracy was 94%. Cyto-cell block analysis reduced the rate of unsatisfactory samples (p < 0.001). Conclusions: The cyto-cell block interpretation improved the efficiency of US-FNA. This simple, fast and low-cost technique should be used as an adjunctive test in thyroid nodule evaluation.
doi:10.1590/2359-3997000000180 pmid:27533613 fatcat:3savpga525hztngwvsk2nlrshi